Causes and Solutions of Diesel Engine Power Shortage

Jan. 25, 2019

1. The air filter is not clean

If the air filter is not clean, the resistance will increase, the air flow rate will decrease, and the aeration efficiency will decrease, resulting in insufficient engine power. Clean the diesel-air filter core or dust off the paper filter as required, and replace the filter if necessary.

2. Exhaust pipe obstruction

Blockage of the exhaust pipe will cause the exhaust to be blocked and fuel efficiency will be reduced. The power drops. Check for increased exhaust resistance due to excessive carbon deposition in the exhaust pipe. General exhaust pressure should not exceed 3.3 KPA, usually should always clear the exhaust pipe carbon deposits.

3. The fuel supply advance angle is too big or too small

Too large or too small fuel supply advance will cause the fuel injection time of the oil pump to be too early or too late (if the fuel injection time is too early, the fuel will not burn enough, too late will emit white smoke, the fuel will also burn insufficiently), so the combustion process is not in the best condition. At this point, check whether the injector shaft coupling screw is loose or, if loosened, re-adjust the fuel supply advance angle and tighten the screw as required.

4. Piston and cylinder sleeve strain

As the piston and cylinder liner are badly pulled or worn out and the piston ring binds the friction loss increases, the mechanical loss of the engine increases, the compression ratio decreases, the ignition is difficult or the combustion is not sufficient, the lower inflation increases and the air leakage becomes serious. At this point, the cylinder liner, piston and piston ring should be replaced.

5. Fuel system malfunction

(1). Fuel filter or pipeline into the air or obstruction, resulting in oil flow is not smooth, lack of power, and even difficult to catch fire. The air entering the pipeline should be cleared, diesel fuel filter should be cleaned and replaced if necessary.

(2) Fuel injection couple damage caused by oil leakage, bite death or poor atomization, this time easy to lead to cylinder shortage, engine power shortage. Clean, grind or replace in time.

(3) Insufficient fuel supply of fuel injection pump will also cause power shortage, should be checked, repaired or replaced in time, and the fuel supply of fuel injection pump should be readjusted.

6. Cooling and lubrication system malfunction

The overheating of diesel engine is caused by the failure of cooling or lubricating system. In this case, the water temperature and oil temperature are too high, and it is easy to get stuck in the cylinder or piston ring. When the exhaust temperature of the diesel engine increases, check the cooler and radiator to remove the scale.

7. Cylinder head group malfunction

(1) Because of the leakage of exhaust gas, the air intake is insufficient or the exhaust gas is mixed in the intake, which leads to the insufficient combustion of fuel oil and the decrease of power. The fitting surface of valve and valve seat should be repaired to improve its sealing and, if necessary, to replace it.

(2) The leakage of air from the interface between the cylinder head and the body will cause the air in the cylinder block to enter the waterway or oil channel, and cause the coolant to enter the engine body. If not found, it will lead to "slippage" or black smoke, which will cause the engine to be powerless. As the cylinder pad is damaged, there will be an air flow from the cylinder pad when the speed changes, and there will be blisters in the gasket when the engine is running. At this time, the cylinder head nut should be tightened or the cylinder head gasket should be replaced in accordance with the prescribed torque.

(3) Incorrect valve clearance will cause air leakage, resulting in engine power drop, or even difficult to catch fire. The valve clearance should be readjusted.

(4) Damage to the valve spring can cause difficulty in valve return, valve leakage, and reduced gas compression ratio, resulting in insufficient engine power. The damaged valve spring should be replaced in time.

(5) Gas leakage or copper pad damage to the injector may lead to cylinder failure, resulting in insufficient engine power. Repair should be removed and damaged parts replaced. If the inlet temperature is too low, the heat loss will increase.

This situation will be accompanied by abnormal sound and oil pressure drop, which is caused by oil channel plugging, oil pump damage, oil filter plugging, or oil hydraulic pressure is too low or even no oil. At this time, detachable diesel engine side cover, check the big end of the connecting rod side and clearance, to see whether the connecting rod head can move back and forth, if can not move, then indicates that has gnawed, should overhaul or replace the connecting rod bush.

For a turbocharged diesel engine, in addition to the above reasons, the power of the diesel engine can also be reduced if the bearing of the supercharger is worn and the intake pipe of the press and turbine is blocked or leaked by dirt. When the supercharger appears above, the bearing should be repaired or replaced separately, the inlet pipe should be cleaned, the shell should be cleaned, the impeller should be cleaned, and the joint nuts and clamps should be tightened.